of boston



G. S. HOLLISTER AND E. B. COOPER.

OIL WELL HEATER.

APPLICATION FILED MAY 7| I9I9. RENEWED JUNE II. I920.

Patented. Nov. 309 1920.

2 SHEETS-SHEEI l.

G. S. HOLLISTER AND E. B. COOPER.

OIL WELL HEATER.

APPLICATION HLED MA1/1,1919. RENEwEn 1u11e11.192o.

f1 ,360941645 Patented Nov. 30, 1920.

2 SHEETS--SHEEI 2.

vto be lowered like a plummet, through the Usme PATENT @met GEORGE s. ftoLnrsTEE, er roeren, ann EDMUND E. coorEE, or NEWTON, Massa- U cnUsET-Ts, Assienoas To oiL WELLS rrEiiEvvnL ooMrANY, or Bos'rom MASSACHUSETTS, conronnrion 0E r/IAss....orrusETTs.`

OIL-WELL HEATER.

Patented Nov. 30, 1920.

Application `filed Mayr?, 1919l Serial No. 295.305. Renewed .Tune 11, 1920. Serial No. 388,350.

` To riz/. whom it may concern Be it .known that We, Grenen tl. Horusprovements in Oil-Tell Heaters, of which the following is a specification. iliis invention relates to a heater adapted 'usual driven tube oi" an oilv Well, and into an enlarged oil-containing cavity or chamloer at the lower end ot the tube, the heater being provided with electrical heating means adapted to heat the oil in said chamber and melt matter partially solidified on the chamber' Walls, thus removing obstructions to the freeentrance vof oil into the chamber Jfrom the surrounding oil-bearing terrain.

The. invention has for its' object to proy Vvide certain improvements looking to the increased eliiciency, durability, and usefulness of a heater for the ypurpose above 1ndicated. Y f

y The invention iseinbodied in the improvements which We will new proceed to describe and claim.V

@if the accompanyingdrawings forming Figure 1 represents in section a portion of an oilwell, and in elevation, a heater .einbodying'our invention, loweredl into the bottoinpoition of the Well.

.f Fig. 2 is an enlarged section on line 24-2 Fig. 3 is a section on lineA-e-B of Fig. 2. Fig.'4 isaside View offra portionof one of the insulating'cores hereinafter described.

Fig. 5 is an end view of the core shown by Fig. 4.

Fig.l 6 is a View similar to Fig. 4, showing Y a different form of core.

Figl 'Tisan end vievv of the Vforno shown by Fig, 6.

8 is a Vfragmentary View showing in elevation, portions of the suspending cable,`

- and partly in section portions of the con- Figli'is a view similar to Fig. 6. shewm ing a different construction of the liquidtight casing hereinafter referred to.

Fig. 12 is asection on line 12-12 of Fig. 11. Y Y,

The same reiferencecharacters indicate the saine parts in all oi theligures.

Our improved heater includes a plurality of spaced apart insulating cores 12 or 12a,

each having external grooves to engage re- Y sistance coils, and internal ducts to conduct coil-connecting Wires. Asv shown by Figs. tand 5., each core may be cylindrical and provided With a helicalv groove 13. :is

shown by Figs. 6 and7, each core may be of approximately triangular form and provided with interrupted coil-receivinggrooves 13. .The ends of, the cores are preferably reduced to torni studs 14 at their opposite ends, the studs at the lower ends of the grooves being engaged With `sockets in a lower head 15 'forming a part ot' the casing hereinaitter described., the studs at the upper ends of the grooves being engaged with sockets in a plate 16 inserted in the casing. Each core is provided With a longitudinal central duct 17 through which pass'the coilconnecting Wires hereinafter described.

The above-mentioned casing is of liquidtio'ht construction to exclude oil from its interior, and may be composed of an elongated tubular body 18having a liquid-tight connection with the lower head 15, and an upper head 19 having a liquid-tight connection head having an opening 20 for the passage 0i. insulating lead Wires 21 and 22.

Engaged with the core grooves above described are helical resistance coils 23 connected in series by coil-connecting Wires 24 extending through the ducts 17 and from coil to coil, the first ,coil 23 of the series and the last conducting Wire 24 `oi the series being `connected yrespectively with thelead Wires 21 and 22, as indicated by Fig. 10.`

With the upper end of the body, the upper f `The portions ofthe lead Wires 2 lfand 22 external to the casing, may be of indeterminate length, to extend from mouth to bottom of an oil Well. VSaid external porytions are 'inclosed in a iexible tube or sheath 25 of oil-resisting soft metal such as lead, a liquid tight connection being provided between the sheath and the casing at the opening 20. Said connection is provided by a stuffing-box 26 of any suitable construction,

' head 19.

attached to the upper head 19, and receiving the lower end of the sheath 2,the stuiling-box being provided with an adjustable follower or gland adapted to compress packing interposed between the inserted portion of the sheath 25 and the wall on the stuiiingbox.

The sheath 25 andthe inclosed portions of the lead wires constitute a conducting cable.

Extending beside the conducting cable is a suspending cable 28, which may be wire rope, and may be engaged with the casing by means of a hook 30 attached to the upper head 19, as shown by Fig. 2.

lVe prefer to couple the conducting cable to the suspending cable by spaced apart couplings 31, as indicated by Figs. 8 and 9, and formed te permit the winding of the two cables upon a drum above the mouth of the well, the couplings being stored with the cables on the drum. Each coupling is provided with clamping means whereby it is firmly engaged with the cables. As best shown by Fig. 9, each coupling is preterablv composed of a bent metal strip 31, formed to embrace portions of the cable 28 and sheath 25, and bolts 31a connecting the arms of said strip and having heads and nuts bearing on said arms.

The casing is formed to be lowered through the usual driven tube 33 of the oil well into the usual cavity or chamber 34 with which said tube communicates, as shown by Fig. V1. When the casing is thus lowered and the electric circuit is closed, the coils 23 are heated and the casing radiates heat into the body of oil inthe chamber 34.

The lead wires 21 and 22 are inclosed in tubes or coverings 21? and 22a of insulating material. The liquid-tight connection' provided by the4 stuffing-box 26, between the casing, and the sheath 25, preventsv the entra-nce of oil into the casing through the The casing has no opening eX- cepting that in the head 19, so that oil is excluded from its interior. The sheath 25 protects the portions ofthe insulating coverings 21a and 22n which are external to the casing,rfrom injury by oil, these coverings being usually of a material liable to disintegration by oil. The couplings 21 connect* ing the conducting cable with the suspending cable, prevent independent strain on the conducting cable tending to separate the sheath 25 from the stuffing-box 26.

The casing is preferably provided at its opposite ends with tapered portions 36, to facilitate the entrance of the casing into the wellrtube 33.

Figs. 11 and 12 show a different construction of the liquid-tight casing designed to present more heat-radiating surface to the oil in the chamber 34 than the orin shown by Figs. 1, 2 and The said casing includes a chambered portion formed by a cylindrical wall 37, the head 19 and a lower head or bottom 38 having apertures Yloi the lead wires and the conducting wires, a series of independent radiating tubes 39 inclosing the cores, and brazed, or otherwise rigidly secured to the head 38 to form a liquid-tight connection therewith, and a head to which the lower ends of the tubes 39 are similarly connected by brazing or otherwise, to i'orm liquid-tight joints between the lower ends of the tubes 39 and the head 40.

As will be seen by reference to Fig. 12, the tubes 39 are spaced apart so that all portions of their periphcries are in contact with the oil, the diameter of the tubes 39 being such that they collectively present more radiating surface than the periphery of the tubular body 1S. It will be seen that the independent tubes 39 constitute a means equivalent to the tubular body 18 for inclosing and supporting the insulating cores.

le claim:

1. An oil well heater comprising spaced apart insulating cores, resistance coils and coil-connecting wires engaged with said cores, a liquid-tight casing inclosing said cores, coils and wires, and including an upper head having an opening, and provid-fad .i

with a stufiing-box coinciding with said opening, a conducting cable composed of elongated lead wires connected with said coils and extending through said opening and stuiling-box, and an oil-resisting iiexible sheath inclosing the exposed portions of the lead wires outside the casing and extending into the stuffing-box, said stuiling-box and the portion of the sheath within the stuihngbox, constituting a liquid-tight packing, preventing access of oil to said opening and lead wires, and a suspending cable secured to said head and extending beside the conducting table.

2. An oil well heater substantially as specified by claim 1, comprising also coul (lll pling's rigidly secured to the conducting cable and to the suspending cable at spaced intervals, and formed to be stored with the cables on a drum, said couplings preventing thev withdrawal of the conducting cable from the stutling-box by strain exerted 'on the cables'.

In testimony whereof we have aflixed our signatures.

GEORGE S. HOLLISTER. EDMUND B. COOPER. 

